What is "mucoadhesion"

n. adhesion to a mucous membrane

Bioadhesion is the mechanism by which two biological materials are held together by interfacial forces. When relating this mechanism to the pharmaceutical sciences, mucoadhesion describes the attractive forces between a biological material and mucus or mucous membrane. Mucus membranes adhere to epithelial surfaces such as the gastrointestinal tract (GI-tract), the vagina, the lung, the eye, etc. They are generally hydrophilic as they contain many hydrogen macromolecules due to the large amount of water (approximately 95%) within its composition. However, mucin also contains glycoproteins that enable the formation of a gel-like substance. Understanding the hydrophilic bonding and adhesion mechanisms of mucus to biological material is of utmost importance in order to produce the most efficient applications. For example, in drug delivery systems, the mucus layer must be penetrated in order to effectively transport micro- or nanosized drug particles into the body.